Having cleared and cleaned the garage, and parked Becky inside, I have noticed that it feels a little damp. A portable hydrometer shows an RH of 70%. Putting the same hydrometer under the carport and it’s only 60%. There seem to be three options:
Increase the (managed) airflow through the garage.
Seal the garage and use a dehumidifier.
Ditch the garage and use the carport (which is between the house and garage, with a gate at one end, so open only at the front. This will require major negotiations with the wife!
I am concerned that as it is, the garage will only increase the rate / risk of rust. The garage is unheated but has power.
I have read previous threads, but they seem inconclusive. What is the experience and advice of people here?
We live on a pretty humid island. Unless your car has lots of bare metal on it, the meagre coatings put on at the factory will suffice to keep the rust away.
The big threat to our cars is the salt and the fact that they don’t drain very well. Don’t drive in the salty seasons and if you get the car wet make sure it’s dry [leave it in the car port for a bit] before you put it away.
My MX is in the unheated garage which has gaps under the double doors and side door. There is also ventilation where the hip joists sit on the front and back walls.
It goes in there every day and the through air is enough to stop it sweating and it drys after a couple of days, even if not wiped down.
I would increase the ventilation a bit more and save on your energy bills a lot more!!
My garage is attached to the house, it still gets cold in there, I have no heating in there. It’s dry and well ventilated having gaps in the roof space, built like that for air flow. I have a gap around the up and over door which seems to aid the air flow too. A downside to the air gaps is I found mice have been in recently chewing a hole in the bag of bird seed in there. Had mice before a few years ago, it’s only the second time in around 30 years so not bad.
It cleaned alright, but pulled the car out today, and its damp inside, in that it rapidly fogs up. Going to leave it out for a bit, and allow some air to circulate through it.
Strange that it’s like that after only 6 weeks.
Are you sure that it’s not damp inside from a leak?
This will rapidly accelerate fungal growth.
My mates camper van had the same scenario, until he found out there was water ingress and got it sorted.
Good question. You’re measuring relative humidity. Just being cold increases RH but if it’s higher than outside then there is probably trapped moisture in there as well. Ventilation will reduce it, or heating (probably not a good idea if it is uninsulated), or dehumidification.
I’m waiting to see how our integral garage works out in the new house we have just built. It’s been plastered, is fairly well sealed, and I did have the outside walls insulated; the sectional garage door will also have insulated panels. There’ll be a fridge freezer in there which will make a little bit of heat and it will steal a bit from the room above it which has underfloor heating. . But I am prepared to run a dehumidifier if RH is a problem.
I know the roof has a leak, a whopping leak. In extremis what happens.
However, the failing of the sills started the time when I started the store the car in a (non-leaking) garage, after years of daily commuting and being parked outside.
Back in the day it was common for cars arriving from Japan to be plastered inside with all sorts of microbial growth. It was a topic of much discussion.
I am looking at a similar problem but garage is dry, I work with engines and for storing them we look to get the humidity down to 40% or below. Looking at dehumidifiers currently.
